Strontium Video No. 356k Stream

Discovered in 1790 and first isolated in 1808, strontium is an element that belongs to the group of alkaline-earth metals. It is a soft metal, like lead, and has a silvery color when freshly cut. Pure metal does not occur naturally and can only be produced through processing. It makes up about 0.04 percent of the Earth's crust and is most commonly found in the minerals strontianite (the carbonate) and celestite (the sulfate). Commercially, it is used as an ingredient in red signal flares.

The isotope strontium-90, which has a half-life of 28 years, is considered the most dangerous constituent of radioactive fallout from nuclear explosions. It can replace some of the calcium in foods and ultimately become incorporated into bones and teeth, where it continues to emit electrons and cause radiation injury. Controlled amounts of radioactive strontium have been used as a treatment for bone cancer.